Method for operating an electrical system of a motor vehicle, and motor vehicle

Abstract

A method is disclosed for operating an electrical system of a motor vehicle, said electrical system comprising a first power source for providing an operating voltage for at least one partial onboard network of the electrical system and at least a second power source, wherein an electrically conductive connection of the first power source to the electrical system is monitored for an intentional interruption and, in the event of a detected intentional interruption of the electrically conductive connection, the at least one second power source of the electrical system is separated therefrom or deactivated. A motor vehicle with an onboard electrical system and a control device, for execution of the method, are also disclosed.

The invention claimed is: 
     
       1. A method for operating an electrical system of a motor vehicle, the motor vehicle comprising a motor, and the electrical system comprising a first power source for providing an operating voltage for at least one part of the electrical system and at least a second power source, comprising the steps of:
 monitoring, by a control system of the motor vehicle, an electrically conductive connection of the first power source to the electrical system to detect an interruption of the electrically conductive connection; 
 detecting, by the control system, at least one condition indicative of a voluntary removal of an electrical contact in the electrically conductive connection; 
 detecting, by the control system, an intentional interruption of the electrically conductive connection when both the interruption of the electrically conductive connection is detected and the at least one condition is detected; 
 separating, by the control system, in response to the detected intentional interruption of the electrically conductive connection, the at least one second power source of the electrical system from the electrical system; and 
 deactivating, by the control system, in response to the detected intentional interruption of the electrically conductive connection, the at least one second power source of the electrical system. 
 
     
     
       2. The method of  claim 1 , wherein the monitoring is of the electrically conductive connection located between a negative pole of the first power source and a vehicle mass of the motor vehicle. 
     
     
       3. The method of  claim 1 , wherein the detecting is performed by a current sensor assigned to the first power source for detecting a current flowing through the first power source, wherein the interruption of the electrically conductive connection is detected when the current sensor detects no current flowing through the first power source. 
     
     
       4. The method of  claim 1 , wherein the at least one condition comprises the motor vehicle standing at zero speed, the motor of the motor vehicle being off, an ignition circuit of the motor vehicle being open, or a maintenance mode of the motor vehicle being activated. 
     
     
       5. The method of  claim 1 , wherein the first power source is a first battery bank and the second power source is a direct voltage converter of the electrical system, wherein the direct voltage converter is connected to the electrical system and a second battery bank. 
     
     
       6. The method of  claim 5 , wherein the first battery bank comprises at least one lead-acid battery and the second battery bank comprises at least one lithium-ion battery. 
     
     
       7. The method of  claim 5 , wherein the second battery bank has a safety switch device, wherein the safety switch device is controlled to separate the second battery bank for interrupting the electrically conductive connection with the electrical system. 
     
     
       8. A motor vehicle, comprising:
 a motor; 
 an onboard electrical system, the onboard electrical system further comprising a first power source for providing an operating voltage for at least one part of the onboard electrical system and at least a second power source, and 
 a control device, wherein the control device is configured to: 
 monitor an electrically conductive connection of the first power source to the onboard electrical system to detect an interruption of the electrically conductive connection; 
 detect at least one condition indicative of a voluntary removal of an electrical contact in the electrically conductive connection; 
 detect an intentional interruption of the electrically conductive connection when both the interruption of the electrically conductive connection is detected and the at least one condition is detected; 
 separate, in response to the detected intentional interruption of the electrically conductive connection, the at least one second power source of the onboard electrical system from the onboard electrical system; and 
 deactivate, in response to the detected intentional interruption of the electrically conductive connection, the at least one second power source of the onboard electrical system. 
 
     
     
       9. The motor vehicle of  claim 8 , wherein the control device is configured to monitor the electrically conductive connection located between a negative pole of the first power source and a vehicle mass of the motor vehicle. 
     
     
       10. The motor vehicle of  claim 8 , wherein the control device is configured to detect the intentional interruption of the electrically conductive connection using a current sensor assigned to the first power source for detecting a current flowing through the first power source, wherein the interruption of the electrically conductive connection is detected when the current sensor detects no current flowing through the first power source. 
     
     
       11. The motor vehicle of  claim 8 , wherein the at least one condition comprises the motor vehicle standing at zero speed, the motor of the motor vehicle being off, an ignition circuit of the motor vehicle being open, or a maintenance mode of the motor vehicle being activated. 
     
     
       12. The motor vehicle of  claim 8 , wherein the first power source is a first battery bank and the second power source is a direct voltage converter of the onboard electrical system, wherein the direct voltage converter is connected to the onboard electrical system and a second battery bank. 
     
     
       13. The motor vehicle of  claim 12 , wherein the first battery bank comprises at least one lead-acid battery and the second battery bank comprises at least one lithium-ion battery. 
     
     
       14. The motor vehicle of  claim 12 , wherein the second battery bank has a safety switch device, wherein the safety switch device is controlled to separate the second battery bank for interrupting the electrically conductive connection with the onboard electrical system.